In Vitro Antimelanoma Properties of Verbena officinalis Fractions.

Verbena officinalis is commonly used in traditional medicine to treat many ailments. Extracts of this plant are therapeutic agents for the potential treatment of different diseases, including colorectal and liver cancers, but have not been explored for their anti-melanoma potential so far. The goal of the current work was to prepare a methanolic extract and fractionate it using hexane, chloroform, ethyl acetate, butanol, and acetone to get semi-purified products. These semi-purified fractions were studied for their potency against melanoma cell lines. The three potent fractions (HA, VO79, and EA3) demonstrated 50% inhibition concentration (IC50) values as low as 2.85 µg/mL against the LOX IMVI cell line. All three fractions showed similar potency in inhibiting the growth of the B16 cells, a murine melanoma cell line. Based on high-resolution mass spectrometry (HRMS) data, for the first time, we report on lupulone A from this plant. LC-MS data also indicated the presence of hedergonic acid, serjanic acid, and other compounds in V. officinalis extracts.

Metabolic Profiling by GC-MS, In Vitro Biological Potential, and In Silico Molecular Docking Studies of Verbena officinalis.

Verbena officinalis L. is a traditionally important medicinal herb that has a rich source of bioactive phytoconstituents with biological benefits. The objective of this study was to assess the metabolic profile and in vitro biological potential of V. officinalis. The bioactive phytoconstituents were evaluated by preliminary phytochemical studies, estimation of polyphenolic contents, and gas chromatography-mass spectrometry (GC-MS) analysis of all fractions (crude methanolic, n-hexane, ethyl acetate, and n-butanol) of V. officinalis. The biological investigation was performed by different assays including antioxidant assays (DPPH, ABTS, CUPRAC, and FRAP), enzyme inhibition assays (urease and α-glucosidase), and hemolytic activity. The ethyl acetate extract had the maximum concentration of total phenolic and total flavonoid contents (394.30 ± 1.09 mg GAE·g-1 DE and 137.35 ± 0.94 mg QE·g-1 DE, respectively). Significant antioxidant potential was observed in all fractions by all four antioxidant methods. Maximum urease inhibitory activity in terms of IC50 value was shown by ethyl acetate fraction (10 ± 1.60 µg mL-1) in comparison to standard hydroxy urea (9.8 ± 1.20 µg·mL-1). The n-hexane extract showed good α-glucosidase inhibitory efficacy (420 ± 20 µg·mL-1) as compared to other extract/fractions. Minimum hemolytic activity was found in crude methanolic fraction (6.5 ± 0.94%) in comparison to positive standard Triton X-100 (93.5 ± 0.48%). The GC-MS analysis of all extract/fractions of V. officinalis including crude methanolic, n-hexane, ethyl acetate, and n-butanol fractions, resulted in the identification of 24, 56, 25, and 9 bioactive compounds, respectively, with 80% quality index. Furthermore, the bioactive compounds identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between ligands and enzymes (urease and α-glucosidase). In conclusion, V. officinalis possesses multiple therapeutical potentials, and further research is needed to explore its use in the treatment of chronic diseases.